CHICAGO (CBS) – Every summer we hear about bacteria like E. coli in the lake water which leads to swimming bans at some beaches, but what about the sand? The CBS 2 Investigators checked out what effect does the bacteria have on the beach.

Geologist Richard Whitman, one of the nation’s top sand experts, says that beach sand should be tested for potential E. coli contamination.

“The truth is that no one knows – no one in the world knows what the real risk is,” Whitman said.

The potential risk was a surprise to families we talked to at 63rd Street beach.

“I’d heard that about the water, but I had never heard that about the sand,” said Therese Byrne, who was visiting the beach with her young children. “Our kids come here, they play in the sand, they practically eat it.”

According to Whitman, “there’s a relationship between the concentration of E-coli and the amount of diarhea you get.” Whitman worries “that same relationship might occur in the sands as people play in it.”

The 2-Investigators asked Whitman’s team to test the sand at five Chicago beaches — Calumet, 63rd Street, Oak Street, North Ave and Montrose beach. The day we tested it was cool and windy with high waves, and Whitman said the results showed that the beaches were “some of the cleanest I’ve ever seen.”

Although our test showed little bacteria, experts say there is a greater risk after a string of hot, steamy days with calm waves. In past sand tests at 63rd street beach Whitman has found bacterial indicators as high or higher than that in the water and they stay in the sand much longer than the water.

Whitman says the three to four foot strip where the waves meet the sand have the highest concentration of E. coli indicators, the area Whitman says beachgoers should probably “stay away from, I’d be happier just a couple of – maybe 5-feet away, inland,” Whitman said.

Brendan Daley, Director of Strategic Development for the Chicago Park District, said that the city has been working to minimize risk for playing in the sand. That work includes using dogs to shoo away the birds whose droppings help contribute to the high levels of E.coli.

“I think we’re doing what we should be doing to make sure that the beaches are healthy and clean,” Daley said.

Right now, the E.P.A. does not have a standard for bacteria in beach sand. This is a new area of research and why Dr. Whitman hopes much more testing will be done.

“As long as we have people in close contact with the sand, I think it’s very important to understand what the risk is?” Whitman said.

We will be testing the sand again.

For now, Whitman says parents should try to make sure kids don’t put sand in their mouths and wash their hands when they’re done playing on the beach.

Acknowledging his state has “come under the harsh glare of criticism” over a controversial new “religious freedom” law, Indiana Gov. Mike Pence said he wants state lawmakers to pass new legislation that makes clear businesses cannot discriminate against gay and lesbian couples.

Police said the robbers used a prop in at least two holdups in the Fuller Park neighborhood. They set up a road construction barrel in the street, and when a motorist gets out of his or her car to move it aside, the robbers pounce.

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